ant-design-vue/components/timeline/Timeline.jsx

import classNames from 'classnames';
import PropTypes from '../_util/vue-types';
import {
  getOptionProps,
  initDefaultProps,
  filterEmpty,
  getComponentFromProp,
} from '../_util/props-util';
import { cloneElement } from '../_util/vnode';
import TimelineItem from './TimelineItem';
import Icon from '../icon';
import { ConfigConsumerProps } from '../config-provider';

export const TimelineProps = {
  prefixCls: PropTypes.string,
  /** 指定最后一个幽灵节点是否存在或内容 */
  pending: PropTypes.any,
  pendingDot: PropTypes.string,
  reverse: PropTypes.bool,
  mode: PropTypes.oneOf(['left', 'alternate', 'right']),
};

export default {
  name: 'ATimeline',
  props: initDefaultProps(TimelineProps, {
    reverse: false,
  }),
  inject: {
    configProvider: { default: () => ({}) },
  },
  render() {
    const { prefixCls: customizePrefixCls, reverse, mode, ...restProps } = getOptionProps(this);
    const getPrefixCls = this.configProvider.getPrefixCls || ConfigConsumerProps.getPrefixCls;
    const prefixCls = getPrefixCls('timeline', customizePrefixCls);

    const pendingDot = getComponentFromProp(this, 'pendingDot');
    const pending = getComponentFromProp(this, 'pending');
    const pendingNode = typeof pending === 'boolean' ? null : pending;
    const classString = classNames(prefixCls, {
      [`${prefixCls}-pending`]: !!pending,
      [`${prefixCls}-reverse`]: !!reverse,
      [`${prefixCls}-${mode}`]: !!mode,
    });
    const children = filterEmpty(this.$slots.default);
    // // Remove falsy items
    // const falsylessItems = filterEmpty(this.$slots.default)
    // const items = falsylessItems.map((item, idx) => {
    //   return cloneElement(item, {
    //     props: {
    //       last: falsylessItems.length - 1 === idx,
    //     },
    //   })
    // })
    const pendingItem = !!pending ? (
      <TimelineItem pending={!!pending}>
        <template slot="dot">{pendingDot || <Icon type="loading" />}</template>
        {pendingNode}
      </TimelineItem>
    ) : null;

    const timeLineItems = !!reverse
      ? [pendingItem, ...children.reverse()]
      : [...children, pendingItem];

    // Remove falsy items
    const truthyItems = timeLineItems.filter(item => !!item);
    const itemsCount = truthyItems.length;
    const lastCls = `${prefixCls}-item-last`;
    const items = truthyItems.map((ele, idx) =>
      cloneElement(ele, {
        class: classNames([
          !reverse && !!pending
            ? idx === itemsCount - 2
              ? lastCls
              : ''
            : idx === itemsCount - 1
            ? lastCls
            : '',
          mode === 'alternate'
            ? idx % 2 === 0
              ? `${prefixCls}-item-left`
              : `${prefixCls}-item-right`
            : mode === 'right'
            ? `${prefixCls}-item-right`
            : '',
        ]),
      }),
    );

    const timelineProps = {
      props: {
        ...restProps,
      },
      class: classString,
      on: this.$listeners,
    };
    return <ul {...timelineProps}>{items}</ul>;
  },
};